1. Field of the Invention
The present invention relates to a device for treating heart failure. More specifically, the invention relates to a cardiac harness having electrodes for providing defibrillation and/or pacing/sensing therapies. The design of the cardiac harness provides electrodes integrated with the cardiac harness having an impedance that optimize the compatibility of the system with commercially available internal cardioverter defibrillators.
2. General Background and State of the Art
Cardiac harnesses, such as those disclosed in U.S. Ser. No. 10/704,376 (“the '376 application”), may be used to treat cardiac heart failure. The entire contents of the '376 application is incorporated herein by reference. To treat other heart failures, including cardiac arrhythmias, the cardiac harness of the '376 application may include electrodes that are connected to an implantable cardioverter defibrillator (“ICD”), which are well known in the art. Such electrodes are capable of delivering a defibrillating electrical shock from the ICD to the heart. These electrodes may also provide pacing/sensing functions to the heart to treat cardiac failures, including bradycardia and tachycardia.
It is desirable to have the cardiac harness with electrodes be compatible with commercially available ICDs and defibrillation capable cardiac resynchronization therapy (“CRT-D”) and pulse generators (“PG”), such as those from Guidant, Medtronic, and St. Jude Medical. In order to be compatible with these commercially available ICDs and CRT-D PGs the electrodes of the cardiac harness must have an appropriate electrical impedance. If the system (cardiac harness with electrodes connected to a power source) has an impedance that is too low, the system could become damaged. On the other hand, if the system has an impedance that is too high, the system may produce an insufficient amount of electric current to travel across the cardiac tissue to sufficiently depolarize a critical amount of cardiac tissue to result in termination of the fibrillating wavefronts. Therefore, what is needed is a cardiac harness having defibrillation and/or pacing/sensing capabilities, wherein the electrodes of the cardiac harness have an impedance that is within an appropriate range.